High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polym...High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polymer/MXene nanocom-posites remains challenging owing to the limited flame-retardant properties of MXene itself.This study prepared a novel MXene@Ag@PA hybrid material via radiation modification and complexation reaction.This material was used to further enhance the key properties of ethylene-vinyl acetate(EVA),such as its mechanical properties,thermal conductivity,flame retardancy,and electromagnetic shielding.The addition of two parts of this hybrid material increased the thermal conduc-tivity of EVA by 44.2%and reduced its peak exothermic rate during combustion by 30.1%compared with pure EVA.The material also significantly reduced smoke production and increased the residue content.In the X-band,the electromagnetic shielding effectiveness of the EVA composites reached 20 dB.Moreover,the MXene@Ag@PA hybrid material could be used to further enhance the mechanical properties of EVA composites under electron-beam irradiation.Thus,this study contributes to the development of MXene-based EVA advanced materials that are fire-safe,have high strength,and exhibit good electromagnetic shielding performance for various applications.展开更多
Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simp...Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.展开更多
To improve the affinity between separators and electrolyte in lithium-ion battery,microporous polyethylene(PE) separator was grafted of polyacrylamide(PAAm) by radiation.Chemical structure of the PAAmgrafted PE separa...To improve the affinity between separators and electrolyte in lithium-ion battery,microporous polyethylene(PE) separator was grafted of polyacrylamide(PAAm) by radiation.Chemical structure of the PAAmgrafted PE separators(denoted as PE-g-PAAm) was characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.Properties of the pristine PE and PE-g-PAAm were tested by scanning electron microscope,liquid electrolyte uptake and lithium-ion conductivity.Electrochemical performances of the grafted PE separators(up to 0.76 × 10^(-3) S/cm of ionic conductivity at room temperature) were much better than pristine PE,and performance of the battery with the grafted separator behaved better than with the virgin PE separator,under the same condition(assembled in Ar-filled glove box).展开更多
Ionizing radiation is a promising method for dye degradation or textile coloration using commercial azo dyes and small molecular weight organic dyes. Thus, the stability of the molecular structure of an azo dye is imp...Ionizing radiation is a promising method for dye degradation or textile coloration using commercial azo dyes and small molecular weight organic dyes. Thus, the stability of the molecular structure of an azo dye is important under ionizing radiation. Disperse Blue 79, as an example azo dyes, was irradiated with gamma rays or electron beam (EB) to investigate the radiation-induced effects on the molecular structure. Ultraviolet visible spectroscopy (UV Vis), nuclear magnetic resonance (NMR) spectra analysis, and mass spectrometry (MS) studies indicated that acetoxy and methoxyl were easily cleaved on the irradiation of the aqueous dye solution but retained a stable structure on the irradiation of the powder form. Gamma rays and EB showed similar effects on the decomposition process. Chromaticity changes using the Lab* method showed that the dye turned to dark yellow and the value of b* of the irradiated dyes increased with the increasing absorbed dose, which indicated that Disperse Blue 79 could be partly decomposed in an aqueous solution This work was nancially supported by the National Natural Science Foundation of China (Nos. 11875313, 11605274, and 11575277). Xiao-Jun Ding and Ming Yu contributed equally to this work. & Jing-Ye Li jyli@shnu.edu.cn 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Lab of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China with an absorbed dose of 10 kGy. Furthermore, the results demonstrated that the chemical stability of the Disperse Blue 79 under ionizing radiation are different in its powder form with the dye in the aqueous solution.展开更多
This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil...This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.展开更多
While the high-energy radiation effects on polypropylene, which are crucial for the cable industry for nuclear power plants, have been thoroughly studied, the property changes of PP at low-dose-rate electron-beam irra...While the high-energy radiation effects on polypropylene, which are crucial for the cable industry for nuclear power plants, have been thoroughly studied, the property changes of PP at low-dose-rate electron-beam irradiation are far from elucidated. Herein, the influence of electron-beam irradiation on the structure and properties of PP was examined. The static EB irradiation conditions were 1.2 MeV at a low dose rate of 20 kGy/h to achieve absorbed doses ranging from 45, to 60, 100, and 200 kGy.The molecular structure was first evaluated by measuring the carboxyl index and the relative radical concentrations via Fourier transform infrared spectroscopy and electron spin resonance, respectively. Mechanical, differential scanning colorimetric, and rheological tests were carried out to further investigate the changes in the properties(tensile, crystalizing, and viscoelastic properties) of irradiated PP, which showed good agreement with the structural analysis results. We found that radio-oxidative degradation(chain scission) was predominant, which can be due to the low dose rate facilitating oxygen diffusion into the PP matrix during electron-beam irradiation.展开更多
Gamma-ray irradiation technique is an effective method for preparing graphene aerogel(GA).The effective reduction and self-assembly of graphene oxide(GO) sheets into 3D porous GA in ethylenediamine(EDA) aqueous soluti...Gamma-ray irradiation technique is an effective method for preparing graphene aerogel(GA).The effective reduction and self-assembly of graphene oxide(GO) sheets into 3D porous GA in ethylenediamine(EDA) aqueous solution under the protection of nitrogen have been achieved via γ-ray irradiation.The reduction degree and self-assembly process,which can be controlled by varying EDA dose and irradiation dose,are investigated by X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,X-ray diffractometer,and thermogravimetric analysis.A reduction mechanism is proposed for interactions among EDA molecules,active radicals from the radiolysis of water,and oxygen-containing groups on GO sheets.展开更多
Silver nanoclusters(AgNCs)are a new type of nanomaterials with similar properties to molecules and unique applications.The applications of AgNCs can be significantly expanded by combining them with different matrix ma...Silver nanoclusters(AgNCs)are a new type of nanomaterials with similar properties to molecules and unique applications.The applications of AgNCs can be significantly expanded by combining them with different matrix materials to obtain AgNC composites.Using irradiation techniques,we developed a simple two-step method for preparing silver nanocluster composites.First,polyacrylic acid(PAA)chains were grafted onto the surface of a PE film as templates(PE-g-PAA).Subsequently,silver ions were reduced in situ on the surface of the template material to obtain the AgNC composites(AgNCs@PE-g-PAA).The degree of AgNC loading on the composite film was easily controlled by adjusting the reaction conditions.The loaded AgNCs were anchored to the carboxyl groups of the PAA and wrapped in the graft chain.The particle size of the AgNCs was only 4.38±0.85 nm,with a very uniform particle size distribution.The AgNCs@PE-g-PAA exhibited fluorescence characteristics derived from the AgNCs.The fluorescence of the AgNCs@PE-g-PAA was easily quenched by Cr^(3+)ions.The composite can be used as a fluorescence test paper to realize visual detection of Cr^(3+).展开更多
With the growing threat of airborne epidemics,there has been an increasing emphasis on personal protection.Masks serve as our primary external defense against bacteria and viruses that might enter the respiratory trac...With the growing threat of airborne epidemics,there has been an increasing emphasis on personal protection.Masks serve as our primary external defense against bacteria and viruses that might enter the respiratory tract.Hence,it’s crucial to develop a polypropylene(PP)nonwoven fabric with quick antibacterial capabilities as a key component for masks.This study introduces silver nanoclusters(AgNCs)into non-woven PP using radiation technology to infuse antibacterial properties.Initially,a solid ligand(PP-g-PAA)was procured via radiation grafting of the ligand polyacrylic acid(PAA),which was incorporated into the nonwoven PP with the aid of a crosslinking agent at a lower absorbed dosage.Subsequently,AgNCs were synthesized in situ on PP-g-PAA via an interaction between PAA and AgNCs,leading directly to the formation of AgNCs@PP-g-PAA composites.Owing to the hydrophilicity of PAA,AgNCs@PP-g-PAA maintains good moisture permeability even when the voids are heavily saturated with PAA gel,preventing droplet aggregation by diffusing droplets on the surface of the material.This feature enhances the comfort of the masks.Most importantly,due to the incorporation of AgNCs,AgNCs@PP-g-PAA demonstrates outstanding antibacterial effects against Escherichia coli and Staphylococcus aureus,nearly achieving an instant“touch and kill”outcome.In conclusion,we synthesized a modified nonwoven fabric with significant antibacterial activity using a simple synthetic route,offering a promising material that provides improved personal protection.展开更多
文摘High-performance MXene-based polymer nanocomposites are well-suited for various industrial applications owing to their excellent mechanical,thermal,and other properties.However,the fabrication of flame-retardant polymer/MXene nanocom-posites remains challenging owing to the limited flame-retardant properties of MXene itself.This study prepared a novel MXene@Ag@PA hybrid material via radiation modification and complexation reaction.This material was used to further enhance the key properties of ethylene-vinyl acetate(EVA),such as its mechanical properties,thermal conductivity,flame retardancy,and electromagnetic shielding.The addition of two parts of this hybrid material increased the thermal conduc-tivity of EVA by 44.2%and reduced its peak exothermic rate during combustion by 30.1%compared with pure EVA.The material also significantly reduced smoke production and increased the residue content.In the X-band,the electromagnetic shielding effectiveness of the EVA composites reached 20 dB.Moreover,the MXene@Ag@PA hybrid material could be used to further enhance the mechanical properties of EVA composites under electron-beam irradiation.Thus,this study contributes to the development of MXene-based EVA advanced materials that are fire-safe,have high strength,and exhibit good electromagnetic shielding performance for various applications.
基金This work was supported by the National Natural Science Foundation of China(Nos.11875313,12075153,and 11575277).
文摘Membrane fouling is always the biggest problem in the practice of membrane separation technologies,which strongly impacts their applicability,separation efficiency,cost effectiveness,and service lifespan.Herein,a simple but effective 3D modification approach was designed for permanently functionalizing polymeric membranes by directly cross-linking polyvinyl alcohol(PVA)under gamma-ray irradiation at room temperature without any additives.After the modification,a PVA layer was constructed on the membrane surface and the pore inner surface of polyvinylidene fluoride(PVDF)membranes.This endowed them with good hydrophilicity,low adsorption of protein model foulants,and easy recoverability properties.In addition,the pore size and distribution were customized by controlling the PVA concentration,which enhanced the rejection ability of the resultant membranes and converted them from microfiltration to ultrafiltration.The crosslinked PVA layer was equipped with the resultant membranes with good resistance to chemical cleaning by acidic,alkaline,and oxidative reagents,which could greatly prolong the membrane service lifetime.Furthermore,this approach was demonstrated as a universal method to modify PVDF membranes with other hydrophilic macromolecular modifiers,including polyethylene glycol,sodium alginate,and polyvinyl pyrrolidone.This modification of the membranes effectively endowed them with good hydrophilicity and antifouling properties,as expected.
基金supported by National Science Foundation of China(Grants 11575277,11175234,11505270,51473183 and 11475246)
文摘To improve the affinity between separators and electrolyte in lithium-ion battery,microporous polyethylene(PE) separator was grafted of polyacrylamide(PAAm) by radiation.Chemical structure of the PAAmgrafted PE separators(denoted as PE-g-PAAm) was characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy.Properties of the pristine PE and PE-g-PAAm were tested by scanning electron microscope,liquid electrolyte uptake and lithium-ion conductivity.Electrochemical performances of the grafted PE separators(up to 0.76 × 10^(-3) S/cm of ionic conductivity at room temperature) were much better than pristine PE,and performance of the battery with the grafted separator behaved better than with the virgin PE separator,under the same condition(assembled in Ar-filled glove box).
基金financially supported by the National Natural Science Foundation of China(Nos.11875313,11605274,and 11575277)
文摘Ionizing radiation is a promising method for dye degradation or textile coloration using commercial azo dyes and small molecular weight organic dyes. Thus, the stability of the molecular structure of an azo dye is important under ionizing radiation. Disperse Blue 79, as an example azo dyes, was irradiated with gamma rays or electron beam (EB) to investigate the radiation-induced effects on the molecular structure. Ultraviolet visible spectroscopy (UV Vis), nuclear magnetic resonance (NMR) spectra analysis, and mass spectrometry (MS) studies indicated that acetoxy and methoxyl were easily cleaved on the irradiation of the aqueous dye solution but retained a stable structure on the irradiation of the powder form. Gamma rays and EB showed similar effects on the decomposition process. Chromaticity changes using the Lab* method showed that the dye turned to dark yellow and the value of b* of the irradiated dyes increased with the increasing absorbed dose, which indicated that Disperse Blue 79 could be partly decomposed in an aqueous solution This work was nancially supported by the National Natural Science Foundation of China (Nos. 11875313, 11605274, and 11575277). Xiao-Jun Ding and Ming Yu contributed equally to this work. & Jing-Ye Li jyli@shnu.edu.cn 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 The Education Ministry Key Lab of Resource Chemistry, Shanghai Key Lab of Rare Earth Functional Materials, College of Chemistry and Materials Science, Shanghai Normal University, Shanghai 200234, China with an absorbed dose of 10 kGy. Furthermore, the results demonstrated that the chemical stability of the Disperse Blue 79 under ionizing radiation are different in its powder form with the dye in the aqueous solution.
文摘This paper presents a superhydrophobic melamine(ME)sponge(ME-g-PLMA)prepared via high-energy radiation-induced in situ covalent grafting of long-alkyl-chain dodecyl methacrylate(LMA)onto an ME sponge for efficient oil–water separation.The obtained ME-g-PLMA sponge had an excellent pore structure with superhydrophobic(water contact angle of 154°)and superoleophilic properties.It can absorb various types of oils up to 66–168 times its mass.The ME-g-PLMA sponge can continuously separate oil slicks in water by connecting a pump or separating oil underwater with a gravity-driven device.In addition,it maintained its highly hydrophobic properties even after long-term immersion in different corrosive solutions and repeated oil adsorption.The modified ME-g-PLMA sponge exhibited excellent separation properties and potential for oil spill cleanup.
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Science(No.XDA02040300)the National Natural Science Foundation of China(No.11575277)
文摘While the high-energy radiation effects on polypropylene, which are crucial for the cable industry for nuclear power plants, have been thoroughly studied, the property changes of PP at low-dose-rate electron-beam irradiation are far from elucidated. Herein, the influence of electron-beam irradiation on the structure and properties of PP was examined. The static EB irradiation conditions were 1.2 MeV at a low dose rate of 20 kGy/h to achieve absorbed doses ranging from 45, to 60, 100, and 200 kGy.The molecular structure was first evaluated by measuring the carboxyl index and the relative radical concentrations via Fourier transform infrared spectroscopy and electron spin resonance, respectively. Mechanical, differential scanning colorimetric, and rheological tests were carried out to further investigate the changes in the properties(tensile, crystalizing, and viscoelastic properties) of irradiated PP, which showed good agreement with the structural analysis results. We found that radio-oxidative degradation(chain scission) was predominant, which can be due to the low dose rate facilitating oxygen diffusion into the PP matrix during electron-beam irradiation.
基金supported by the National Natural Science Foundation of China(No.11505270)Shanghai Municipal Commission for Science and Technology(No.15ZR1448300)
文摘Gamma-ray irradiation technique is an effective method for preparing graphene aerogel(GA).The effective reduction and self-assembly of graphene oxide(GO) sheets into 3D porous GA in ethylenediamine(EDA) aqueous solution under the protection of nitrogen have been achieved via γ-ray irradiation.The reduction degree and self-assembly process,which can be controlled by varying EDA dose and irradiation dose,are investigated by X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,X-ray diffractometer,and thermogravimetric analysis.A reduction mechanism is proposed for interactions among EDA molecules,active radicals from the radiolysis of water,and oxygen-containing groups on GO sheets.
基金supported by the Gansu Natural Science Foundation (Nos.20JR10RA778 and 20JR10RA777)。
文摘Silver nanoclusters(AgNCs)are a new type of nanomaterials with similar properties to molecules and unique applications.The applications of AgNCs can be significantly expanded by combining them with different matrix materials to obtain AgNC composites.Using irradiation techniques,we developed a simple two-step method for preparing silver nanocluster composites.First,polyacrylic acid(PAA)chains were grafted onto the surface of a PE film as templates(PE-g-PAA).Subsequently,silver ions were reduced in situ on the surface of the template material to obtain the AgNC composites(AgNCs@PE-g-PAA).The degree of AgNC loading on the composite film was easily controlled by adjusting the reaction conditions.The loaded AgNCs were anchored to the carboxyl groups of the PAA and wrapped in the graft chain.The particle size of the AgNCs was only 4.38±0.85 nm,with a very uniform particle size distribution.The AgNCs@PE-g-PAA exhibited fluorescence characteristics derived from the AgNCs.The fluorescence of the AgNCs@PE-g-PAA was easily quenched by Cr^(3+)ions.The composite can be used as a fluorescence test paper to realize visual detection of Cr^(3+).
文摘With the growing threat of airborne epidemics,there has been an increasing emphasis on personal protection.Masks serve as our primary external defense against bacteria and viruses that might enter the respiratory tract.Hence,it’s crucial to develop a polypropylene(PP)nonwoven fabric with quick antibacterial capabilities as a key component for masks.This study introduces silver nanoclusters(AgNCs)into non-woven PP using radiation technology to infuse antibacterial properties.Initially,a solid ligand(PP-g-PAA)was procured via radiation grafting of the ligand polyacrylic acid(PAA),which was incorporated into the nonwoven PP with the aid of a crosslinking agent at a lower absorbed dosage.Subsequently,AgNCs were synthesized in situ on PP-g-PAA via an interaction between PAA and AgNCs,leading directly to the formation of AgNCs@PP-g-PAA composites.Owing to the hydrophilicity of PAA,AgNCs@PP-g-PAA maintains good moisture permeability even when the voids are heavily saturated with PAA gel,preventing droplet aggregation by diffusing droplets on the surface of the material.This feature enhances the comfort of the masks.Most importantly,due to the incorporation of AgNCs,AgNCs@PP-g-PAA demonstrates outstanding antibacterial effects against Escherichia coli and Staphylococcus aureus,nearly achieving an instant“touch and kill”outcome.In conclusion,we synthesized a modified nonwoven fabric with significant antibacterial activity using a simple synthetic route,offering a promising material that provides improved personal protection.
